What characteristic sets streams and rivers apart? a. water quality b. direction of flow c. size d. biodiversity

The characteristic that sets stream and rivers apart is the size. Small rivers may sometimes be referred to as stream, creek, brook, rill, and rivulet. Both are natural flowing watercourse. Thus, the answer to this item is letter C. 

Asmall closed hole formed in an outwash plain or moraine. forms when a  glacier retreats then remains stationary.